SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a327ce8c93189c17ab44a4ade5f08372067411b1618eb5552ab5e585c0780379' 
  AND token = 'jhnLHX+6QaTeVQ3HBsN+vIK2lhStO+DNhlFTZEvPwzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}